Video communication over a wireless link may be challenging due to the relatively large bandwidth typically needed and the low-latency and high reliability constraints of video. The growth of multimedia applications and increased mobile Internet access has created a need for enhancing video delivery in wireless systems. For example, mobile users now expect to receive live sporting events, news updates, movie streaming, and other types of on-demand video on their wireless mobile devices. Wireless video standards have been created to help meet this demand. For example, evolved multimedia broadcast and multicast services (eMBMS) is one such standard.
Unfortunately, wireless channels tend to be lossy due to multipath signals, lost data, and corrupted data. Unicast transmissions can employ automatic repeat request (ARQ) and/or hybrid ARQ (HARQ) to increase the reliability of the transmission. However, for multicast transmissions, implementing ARQ and/or HARQ may lead to network congestion when multiple users request retransmission of different packets. Moreover, each user may have a different channel to the base station so that different users may lose different packets. Thus, transmission could mean sending a large portion of the original content again, leading to inefficient use of bandwidth as well as increased latency for some users.
Thus there are general needs for improved video transmission methods. There are also general needs for making efficient use of wireless bandwidth.